Tight winding device for timepieces



TIGHT WINDING DEVICE FOR TIMEPIECES Filed 001;. 5, 1945 figi .IZZL/JZZ'OJ J 1i .25 017/ inch Z) Patented Mar. 29, 1949 TIGHT WINDING DEVICEFOR TIMEPIECES Joseph Antoine Boninchi, Geneva, Switzerland, assignor toJ. Boninchi & Ses Fils, Geneva, Switzerland, a firm of SwitzerlandApplication October 5, 1945, Serial No. 620,495 In Switzerland November15, 1944 1 Claim.

This invention relates to tight winding devices for time-pieces and moreparticularly to fluid tight winding crowns in which a compressiblepacking provides a sealing joint between the body of the crown and thependant neck of the watch case.

According to U. S. Patent No. 2,405,087, granted on July 30, 1946, tothe same inventor, an ellicient sealing arrangement is provided in whichthe compressible packing has a cylindrical main body fitted about and insealing contact with the pendant neck and spaced radially from the sidewall of the crown recess in which it is lodged and a lower flangeprojecting outwards from the periphery of said main body and compressedbetween and having sealing contact with a shoulder on the outer wall ofthe crown recess and a clamping piece borne by said crown.

The present invention primarily consists in that the cylindrical mainbody of this flanged packing is pressed radially against the pendantneck by a crown-shaped spring capping said main body, and the bottom ofwhich bears on the bottom of the crown recess.

In order that the invention may be completely understood, attention isdirected to the accompanying drawing showing an embodiment of theinvention.

In the drawing:

Fig. l is an axial sectional view of this embodiment and Fig. 2 is anelevation with parts in section of the crown-shaped spring alone,

In the drawing, I designates the case band of a watch case, 2 thependant neck and 3 the winding crown in a, recess 5 of which there islodged a compressible packing 4 which insures the required fluidtightness of the joint between the pendant neck and the crown. Thepacking is formed of a cylindrical main body 4a fitted about the neck 2and a lower flange 4b projecting outwards from the periphery of saidmain body. The cylindrical main body 4a is lodged with radial clearancein the recess 5 of the crown. Also an axial clearance is providedbetween the upper end of the main body 4a and the bottom of the crownrecess 5. Only the flange 4b is compressed at its periphery between ashoulder 6 of the crown and a clamping washer I forced in the lower partof the crown recess and held in place by setting. Obviously the clampingwasher may also be in screw threaded engagement with the crown.

The cylindrical main body la of the packing is pressed radially againstthe pendant neck 2 by a crown-shaped spring-member 8 capping the body laand having resilient lugs 9 extending downwards from its bottom whichbears on the bottom of the crown recess 5. The resilient lugs areslightly arched and their length is rated so that their extremities 9bear on the upper face of the flange ib of the packing thus ensuringdurability of the inward radial pressure of the bellied portion of thelugs against the cylindrical body 4a of the packing. The length of thebody do is rated so as to leave an axial clearance between the outerextremity of this body and the bottom of the recess 5.

Owing to the combined effect of the durable radial pressure put on thebody M by the lugs 9 and of the axial clearance provided between theextremity of said body and the bottom of the crown-shaped spring 8, avery efficient tight joint is obtained with a particularly soft windingof the crown in spite of all the irregularities which occur in themanufacture of the various parts of the device and of the wear of thepacking.

It is to be understood that the number and the shape of the resilientlugs may be chosen at will.

What I claim is:

In a tight winding device for time pieces, the combination with a casebody having a pendant neck fixed thereto, of a crown having an annularrecess, a compressible packing fitted about said neck, and including acylindrical main body spaced radially from the side wall and axiallyfrom the bottom of said recess and a lower flange projecting outwardsfrom the periphery of said main body, a shoulder on the outer wall ofsaid recess, a clamping piece borne by said crown, said flange beingcompressed between and having sealing contact with said shoulder andsaid clamping piece, and a crown-shaped spring member capping said mainbody and bearing with its bottom on the bottom of said recess, saidcrown-shaped member having inwardly bellied resilient lugs extendingdownwards and bearing by their extremities on said flange of the packingso as to exert by their bellied portions a durable inward radialpressure on said cylindrical body of the packing, said body beingthereby in durable sealing contact with said pendant neck.

JOSEPH ANTOINE BONINCHI.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,237,860 Bolle Apr. 8, 19412,399,092 Bolle Apr. 23, 1946 2,405,087 Boninchi July 30, 1946 FOREIGNPATENTS Number Country Date 140,469 Switzerland Nov, 17, 1930 209,993Switzerland Aug, 16, 1940

